- to determine the grade of PPES at Day 1 and Day 21 of ATH008 cream treatment Part I will have four different arms; patients will receive one of the three different doses of drug product (ATH008 cream 1%, ATH008 cream 3% or ATH008 cream 8%) or placebo (ATH008 cream placebo) in repeated doses (twice daily) during a period of 21 days.